I am looking for some information to help my father out. He has a 31 Ford Coupe with a 55 Chevy rear end in it. Its non posi and he wants to put a powertrax unit in it. I want to order it buy want to make sure i order the right part. Anyone who might know what i am looking for? I have 0 experience with these. Thanks.

Eaton has a new posi for the '55-'64 Chevy 8.2 rear end. It fits the standard case so you don't have to use the "P" case. I don't show anything from Power Trax for the '55-'64 8.2 Chevy.

Thanks, i will look into the eaton unit.